Valves for controlling the flow of hydraulic fluids

ABSTRACT

In a fluid-flow control valve of the tilting type an intermediate member interposed between a head and a seating has a surface portion complementary in outline to a rim comprising an adjacent end of an internal wall of the seating which defines a fluid flow passage or port. The surface portion is movable into and out of seating engagement with the rim upon tilting or rocking movement of the head with respect to the seating.

United States Patent 1191 Robinson 1 June 4, 1974 [5 VALVES FOR CONTROLLING THE FLOW 2.968.316 1/1961 Schultz 137/596 OF HYDRAULIC FLUIDS 3,180,354 4/1965 .Grose 251/65 3,555.822 l/l97l Rivetti 60/562 entor: Barry Samuel John Robinson, Cabos 3,575,001 4/1971 Wilson 60/589 near Garstang, England 3,703,079 11/1972 Ingram et al 60/562 [73] Assignee: Girling Limited, Tyseley,

. Birmingham, Engl Primary Examiner-Edgar W. Geoghegan Assistant Examiner-A. M. Zupcic [22] Flled' 1972 Attorney, Agent, or Firm-Imirie and Smiley [21] Appl. No.: 299,397

Related [1.8. Application Data [62] Division of Ser. No. 126,722, March 22, 1971, [57] ABSTRACT abandmed' In a fluid-flow control valve 'of the tilting type an intermediate member interposed between a head and a 122] :LS. (g1. 303/50,B Seating has a surface portion complementary in 58 Ff i 5 line to a rim comprising an adjacent end of an internal 1 0 am 6 589 6 wall of the seating which defines a fluid flow passage or port. The surface portion is movable into and out of seating engagement with the rim upon tilting or rock- [56] References cued ing movement of the head with respect to the seating.

UNlTED STATES PATENTS 2 882,867 4/1959 Thompson 137/609 3 Claims, 3 Drawing Figures 74 v 75' 74 2 l5 7 24 2'4 2] l6 7 5 a 23 V/ l 3 10 1 7 4 Y l s a /////1//1//- I I I I I f 657 ;2 320 25 a 9 PATENTEUJUH 41914 3.814.485 sum 1 or 2 INVENTOR BARRY s, 3- Rosiwson Atfs.

PATENTEDJUH 4 m4 3,814,485

INVENTOR MRRY 5. J. ROBINSON VALVES FOR CONTROLLING THE FLOW OF HYDRAULIC FLUIDS This is a division, of application, Ser. No. 126,722, filed Mar. 22, 1971, now abandoned.

This invention relates to improvements in valve assemblies of the tilting type for controlling the flow of hydraulic fluids of the kind in which a head carried by a stem is normally spring urged into engagement with a relatively fixed seating to close a port or passage surrounded by the seating and communication through the port or passage is established by the application to the stem of a force in a direction to cause the head to tilt or rock against the spring loading about an engagement with the seating at a point spaced radially outwards from the port or passage.

Hitherto, in tilting valve assemblies of the kind set forth, in the closed position, the head and the seating are spring urged into engagement over a substantial area, which may be equal to the area of the head. In such constructions, difficulty may be experienced in obtaining an effective seating engagement between the head and the seating due to deformation of one or both of the mating surfaces, or the presence of dirt or other foreign matter between the surfaces.

According to our invention in a valve assembly of the tilting valve type of the kind set forth for controlling the flow of hydraulic fluids there is interposed between the head and the seating an intermediate member having a surface portion complementary in outline to a rim comprising an adjacent end of an internal wall of the seating which defines the port or passage, and the surface portion is movable into and out of seating engagement with the rim upon tilting or rocking movement of the head with respect to the seating.

The seating engagement between the intermediate member and the seating in the closed. position of valve is effected over a very small area acted upon by the spring loading. Thus any tendency for the efficiency of the seating engagement to be impaired by the deforma' tion of the seating or the head, or the presence of dirt or other foreign matter between the head and the seating, is reduced or substantially eliminated.

Preferably the intermediate member comprises a ball of spherical outline of a diameter greater than that of the rim so that the intermediate member engages with the rim over a circular surface portion which bounds a segment of the sphere.

The ball may be housed within a central recess in the head or the ball may be housed in a counterbored recess in the face of the seating adjacent to the head. In either construction, it is preferred that the recess is of a depth slightly greater than the radius of the ball so that portions of the outer end of the wall defining the recess may be peened over or otherwise deformed towards each other to retain the ball within the recess.

Two embodiment of my invention are illustrated in the accompanying drawings in which:

FIG. I is a longitudinal section through a pedaloperated master cylinder for a vehicle hydraulic braking system incorporating a pair of tilting valves in accordance with my invention;

FIG. 2 is a longitudinal section through a portion of the master cylinder illustrated in FIG. 1 but showing a modified tilting valve; and

FIG. 3 is a section on the line 3--3 of FIG. 2.

In the pedal-operated master cylinder illustrated in FIG. I, l is a body provided with an axially extending bore 2 in which works a cage assembly 3. The cage assembly 3 is mounted on the inner end of an extension 4 of a piston 5 working through a bore 6 in a partition 7 closing one end of the bore 2. The opposite end of the bore 2 is closed by a plug 8 screwed into the bore 2 and provided with a central passage 9 for connection to at least one slave cylinder of a wheel brake.

In the position shown ,in the drawings, communication between the bore 2 and a reservoir for supplying hydraulic fluid to a high pressure pump is established through a port 10 in the cylinder wall by a tilting valve assembly 11 in accordance with my invention. Communication between the bore 2 and a high pressure source, for example the high pressure pump or an hydraulic accumulator supplied by the high pressure pump, through a port 12 spaced axially from the port 10 is cut-off by a second tilting valve assembly 13 of a construction identical with that of the valve assembly 11.

Each tilting valve assembly ll, 13 comprises a union l4 screwed into the outer end of a radial bore 15 of substantial diameter provided in the cylinder wall. The inner end of each bore 15 communicates with a respective port 10 and 12. A head 16 carried by the inner end of a stem 17 is housed with a chamber 18 defined by the space between the inner end of the union l4 and the base of the bore 15. The head 16 is urged towards the inner end of the union 14 by a compression spring 19 acting between thehead l6 and the base of the bore 15, and each stem 17 projects at its outer free end through its respective port 10, 12 into the path of an axially extending shroud 20 of the cage 3 working in the bore 2.

Eachunion 14 is provided with an axially extending passage or port 21 of which the passage or port 21 in the union of the tilting valve assembly 11 is connected to the reservoir, and the passage or port 21 in the union of the tilting valve assembly 13 is connected to the high pressure source.

Each head 16 is formed with a central recess 22 which is aligned with the passage or port 21 and in which is housed a ball 23 of a diameter greater than that of the passage or port 21. The recess 22 is of a depth greater than the radius of the ball 23 so that portions of the head defining the open end of the recess 22 may be peened over or otherwise deformed towards each other to retain the ball 23 in the recess.

Normally the ball 23 is urged into engagement with .a seating 24 in the inner end of the union 14 by the effect of the compression spring 19 acting on the head 16 in which the ball 23 is housed. The seating 24 which comprises the rim or edge of the inner end face of the union 14 which surrounds the inner end of the port or passage 21 is engaged by a circular surface. portion of the ball 23 bounded by a segment of the ball which is received within the port or passage 21.

In the off" position of brake, the valve assembly 11 is held in the open position by the engagement with its stem 17 of the outer end of the shroud 20 under the influence of a return spring 25 acting between the cage assembly 3 and the plug 8. In this position the head 16 of the valve assembly 11 is held in a tilted position against the force in the spring 19 by an engagement be tween the outer edge of the head 16 and the union 14. Since the shroud 20 is spaced from the stem 17 of the valve assembly 13 the ball 23 is held in seating engage ment with its seating 24 due to the force in the spring 10. Thus communication is established between the bore 2 and the reservoir through the port and the port or passage 21, and communication between the bore 2 and the high pressure source of fluid is cut-off.

When the piston 5 is advanced by operation of a pedal, the cage assembly 3 is advanced in the bore 2 to permit the valve assembly 11 to close, and to open the valve assembly 13 so that fluid under pressure from the high pressure source passes to the wheel brake through the port or passage 21, the port 12, the bore 2 and the passage 9.

In the construction illustrated in FIGS. 2 and 3, each of the tilting valve assemblies, of which only the assembly 13 is illustrated, is of modified form and corresponding reference numerals qualified by the suffix a have been applied to corresponding parts.

As illustrated the ball 23a is'located in a counterbored recess 30 at the inner end of the port or passage 21a in the union 14a and the seating rim 24a isformed at the inner end of the recess 30. The ball 23a is retained in the recess 30 by peening' over or deforming a pair of diametrically opposed portions 31 of the wall of the recess 30 at its free end. The recess 30 is of a diameter greater than that of the ball and the axial length or depth of the recess 30 is chosen so that the ballis free to move within the recess in an axial direction towards and away from the seating 24a under the influence of the force in the spring 19a which acts on the ball 23a through the head 16a.

The construction and operation of the embodiment of F I05. 2 and 3 is otherwise the same as that described above with reference to FIG. 1.

We claim:

1. in a master cylinder for a'vehicle hydraulic system comprising a housing having a wall defining a longitudinally extending bore and a first radial port leading into a first radial chamber, a first valve assembly for controlling communication between said first chamber and said longitudinally extending bore at least in one direction. said first valve assembly comprising a first head located within said first chamber. a first stem carrying said first head and extending through said first radial port into said longitudinal extending bore. a first seating in said first chamber located radially outwards of said first head and surrounding a first internal wall defining a first fluid-flow port for connection to a first supply of fluid under pressure. and a first spring for normally applying to said first head a force in a direction to urge said first head into engagement with said first seating to close said first fluid-flow port, a positively actuated piston working in said longitudinally extending bore, means associated with said piston for engagement with said first stem to apply to said first stem upon operation of said piston a force in a direction to cause said first head to tilt against said spring force about an engagement with said first seating at a point spaced radially outwards from said first fluid-flow port whereby communication is established between said first fluid-flow port and saidlongitudinally extending bore, the invention wherein a freely rotatable ball is housed within a counterbored recess in the face of the first seating for movement into and out of engagement with a valve seat defined in the base of said recess upon tilting movement ofsaid first head with respect to said first seating, whereby said' ball is positively disengaged from said valve seat by fluid pressure in said first port on tilting movement of said first head and said ball prevents fluid flow from said bore to said first port irrespective of the position of said first head.

2. A master cylinder as in claim 1 wherein said recess is of a depth at least slightly greater than the radius of said ball, and portions of an outer end of a wall defining said recess are deformed towards each other to retain said ball with said recess.

3. A master cylinder as claimed in claim 1 incorporating a second valve assembly spaced axially from said first valve assembly for controlling communication between a second radial chamber in said housing wall and said longitudinally extending bore through a second radial port at least in one direction, said second valve assembly comprising a second head located within said second chamber, a second stem carrying said second head and extending through said second radial port into said longitudinally extending bore, a second seating in said second chamber located radially outwards of said second head and surrounding a second internal wall defining a second fluid-flow port for connection to a second supply of fluid, and a second spring for normally applying to said second head a force in a direction to urge said second head into engagement with said second seating to close said second fluid-flow port wherein said means associated with said piston comprises a cage assembly for engagement alternatively with said first and second stems.

* l l I I 

1. In a master cylinder for a vehicle hydraulic system comprising a housing having a wall defining a longitudinally extending bore and a first radial port leading into a first radial chamber, a first valve assembly for controlling communication between said first chamber and said longitudinally extending bore at least in one direction, said first valve assembly comprising a first head located within said first chamber, a first stem carrying said first head and extending through said first radial port into said longitudinal extending bore, a first seating in said first chamber located radially outwards of said first head and surrounding a first internal wall defining a first fluid-flow port for connection to a first supply of fluid under pressure, and a first spring for normally applying to said first head a force in a direction to urge said first head into engagement with said first seating to close said first fluid-flow port, a positively actuated piston working in said longitudinally extending bore, means associated with said piston for engagement with said first stem to apply to said first stem upon operation of said piston a force in a direction to cause said first head to tilt against said spring force about an engagement with said first seating at a point spaced radially outwards from said first fluid-flow port whereby communication is established between said first fluid-flow port and said longitudinally extending bore, the invention wherein a freely rotatable ball is housed within a counterbored recess in the face of the first seating for movement into and out of engagement with a valve seat defined in the base of said recess upon tilting movement of said first head with respect to said first seating, whereby said ball is positively disengaged from said valve seat by fluid pressure in said first port on tilting movement of said first head and said ball prevents fluid flow from said bore to said first port irrespective of the position of said first head.
 2. A master cylinder as in claim 1 wherein said recess is of a depth at least slightly greater than the radius of said ball, and portions of an outer end of a wall defining said recess are deformed towards each other to retain said ball with said recess.
 3. A master cylinder as claimed in claim 1 incorporating a second valve assembly spaced axiAlly from said first valve assembly for controlling communication between a second radial chamber in said housing wall and said longitudinally extending bore through a second radial port at least in one direction, said second valve assembly comprising a second head located within said second chamber, a second stem carrying said second head and extending through said second radial port into said longitudinally extending bore, a second seating in said second chamber located radially outwards of said second head and surrounding a second internal wall defining a second fluid-flow port for connection to a second supply of fluid, and a second spring for normally applying to said second head a force in a direction to urge said second head into engagement with said second seating to close said second fluid-flow port wherein said means associated with said piston comprises a cage assembly for engagement alternatively with said first and second stems. 